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LakeQuality

Missisquoi Bay Lake

Franklin County, VermontView mapDirections

D
Nutrient-rich

Nutrients and algae run above the regional average.

↓ down from C at the last regrade

Water temp
No reading
No gauge
Clarity
5.6 ft
Secchi · sampled 2025
Level
No reading
No gauge
Trend
No reading
Not enough history
  • Eutrophic
  • Impaired · Mercury
  • #3 of 5 in the county
  • Public access

Missisquoi Bay Lake in Franklin County, Vermont has a water quality grade of D (Nutrient-rich). Water clarity: 5.6 ft visibility. Phosphorus: 42.8 µg/L. Chlorophyll-a (algae): 12.1 µg/L.

Clarity
5.6 ft
Type
Eutrophic
Phosphorus
42.8 µg/L
Chlorophyll-a
12.1 µg/L
Public access
Yes
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Stays via Stay22

Stays near Missisquoi Bay Lake

Compare lakeside cabins, hotels, and vacation rentals near Missisquoi Bay Lake in Franklin County, Vermont — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water. The water-quality grade measures nutrients and algae, not lodging — cabins and rentals around Missisquoi Bay Lake are listed below.

Top-rated places to stay near Missisquoi Bay Lake

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Missisquoi Bay Lake is a productive, nutrient-rich eutrophic lake in Franklin County, Vermont. Water quality is graded D based on 2 sampling years through 2025. Limited fish-species data available. Public access is available with 3 public boat landings. Compared to the 4 other monitored lakes in Franklin County, Missisquoi Bay Lake ranks #3 for water quality.

Source: EPA Water Quality Portal sampling records, VT DEC, last sampled 2025-08-08. Grade methodology: LakeQuality methodology.

What Missisquoi Bay Lake is good for

From access and monitoring records, not editorial picks.

  • Boat launch3 documented ramps

Swimming Safety

Grade only

Elevated nutrients

Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.

The D is nutrients and algae, not a swimming clearance. Missisquoi Bay Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury, nutrients (phosphorus, nitrogen). Check local advisories before you swim.

Get alerts for Missisquoi Bay Lake

Water Quality Grade: D (Nutrient-rich)

Murky, only visible to about 5.6 ft. Phosphorus 42.8 µg/L. Chlorophyll-a 12.1 µg/L. TSI 55. The letter is not a swimming clearance.

MetricValueGrade
Water Clarity (Secchi Depth)5.6 ftNot graded
Phosphorus42.8 µg/LPoor
Chlorophyll-a (Algae)12.1 µg/LPoor
Trophic State Index (TSI)55Eutrophic

High nutrients, frequent algae, reduced clarity

Recreation & Access

3
Boat Landings
Yes
Public Access
  • Rock RiverPublic
  • Larry GreenePublic
  • Campbells Bay CampgroundSemi-private

Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps

Fishing Missisquoi Bay Lake

EPA Impairment Status

Missisquoi Bay Lake is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 4A).

Causes of impairment

MercuryNutrients (phosphorus, nitrogen)

A Total Maximum Daily Load (TMDL) plan has been approved.

Source: EPA ATTAINS assessment unit VT05-01L01_01 · Official waterbody report · Matched by proximity (2.96 km)

County Ranking

Ranked #3 of 5 lakes in Franklin County

Nearby Lakes With Higher Grades

Missisquoi Bay Lake holds Grade D. 3 nearby lakes hold higher nutrient-and-algae grades — useful for a swim day, not a reason to skip lodging here.

See full comparison →

Nearby Lakes in Franklin County

Frequently asked questions about Missisquoi Bay Lake

Where is Missisquoi Bay Lake?

Missisquoi Bay Lake is a lake in Franklin County, Vermont. LakeQuality grades it D for nutrients and algae. The letter is not a swimming clearance.

What is the water quality grade for Missisquoi Bay Lake?

Missisquoi Bay Lake in Franklin County, Vermont has a water quality grade of D (Nutrient-rich). Water clarity: 5.6 ft visibility. Phosphorus: 42.8 µg/L. Chlorophyll-a (algae): 12.1 µg/L.

Is Missisquoi Bay Lake safe to swim in?

The D is nutrients and algae, not a swimming clearance. Missisquoi Bay Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury, nutrients (phosphorus, nitrogen). Check local advisories before you swim.

Are there boat ramps on Missisquoi Bay Lake?

Missisquoi Bay Lake has 3 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Rock River, Larry Greene, Campbells Bay Campground. Public access is listed as yes.

Where this data comes from

266 measurements from 2 monitoring stations, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • Vermont Dept of Environmental Conservation1VTDECWQ266 samples · 2020–2025

Analytical methods

  • EPA approved Alternate Test Procedure for 4500 P H. Has a 28 day hold without acid preservation.
  • 445.0 ~ EPA; Chlorophyll and Pheophytin in Algae by Fluorescence
  • 2130 B ~ Nephelometric Method
Monitoring station identifiers (2)

Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.

Other records on this page

Impairment status from EPA ATTAINS 303(d) database

Named boat-access points from the USGS National Boat Ramps inventory